The invention relates to an elastic coupling comprising an inside ring, plus an outside ring at least partially encompassing the inside ring, the inside and outside rings being mounted for rotation relative to one another about a common axis and being joined together in a torsionally elastic manner by at least one elastic body of elastomeric material.
Such an elastic coupling is disclosed in DE-OS 39 13 547. The torsional vibration damper shown therein includes a rubber elastic system which is associated both with the rotating ring and with the hub ring in a relatively nonrotating manner in the area of their circumferential surfaces. The rubber elastic system is configured as a circumferential ring which is vulcanized at its inner side to the outer circumferential surface of the hub, and is provided on its outside with a metal sleeve vulcanized to it. The metal sleeve is pressed into the receiving opening of the rotating ring. Furthermore, the previously known coupling has slide ribs which project radially from one of the rings and are supported on the other ring. The slide ribs are associated with the rubber elastic system at an axial distance from it, so as to prevent the wobbling of the rotating ring. It is to be noted, however, that the elastomer must be made from low-damping mixtures for the best possible isolation. When passing through resonance, and at peak torques, this results in very great relative turning of the hub ring with respect to the rotating ring. Due to the high mechanical stresses on the elastic body, and to tensional stresses in the area of the adhered circumferential surfaces and shear stresses within the elastic body, the dynamic properties of the previously known coupling over a long period of use are not very satisfactory.
Furthermore, it is known that, in order to limit the relative rotation between the hub ring and the rotating ring, for example upon the introduction of peak torques, abutments are provided which limit the relative rotation when an allowable turning angle is exceeded. A disadvantage of couplings provided with abutments is the greater expense of production and the irregular transition between the relative rotation of the two rings and the sudden collision limiting the torque peaks. Collision with the abutments is usually accompanied by noise, which is undesirable.
The invention is addressed to the problem of further improving an elastic coupling of the prior art such that a elastic body of low-damping material can be used, which has good dynamic properties over a long period of use even if torque peaks occur frequently, and such that the limiting of the mechanical stress on the elastic body will occur without generating noise.